1. Field of the Invention
This invention relates to a tape transport apparatus for transporting a tape of a video tape recorder and the like.
2. Prior Art
When a video tape recorder is operated in a recording mode or a reproducing mode, a tape is pinched between a capstan and a pinch roller and transported at a predetermined speed by rotatably driving a capstan driven by a capstan motor. And when the video tape recorder is operated in a fast-forward running mode or a rewinding running mode, the tape is wound around a supply reel or a take-up reel by rotatably driving the supply reel or the take-up reel at a high speed by transmitting a driving power of a capstan motor by way of a transmitting mechanism such as a pulley, belt and the like connecting between the supply reel or the take-up reel and the capstan motor with the capstan and the pinch roller disengaged with each other. At the high-speed running mode, a voltage higher than that of a usual running mode such as reproducing mode is applied to the capstan motor so as to thereby rotate at a high rotation speed.
When a winding load is increased due to non-uniform winding or deformation of a tape cassette or the like while the video tape recorder is operated in a fast-forward running mode or a rewinding running mode, the rotation of the capstan motor gets lowered in spite of high voltage applied thereto. In such a case, the electric currency of the capstan motor increases and the capstan motor is heated and thereby there occurs thermal-shut-down which actuates a protect circuit to stop the capstan motor, or otherwise an IC device in a motor driver is destroyed by heat generation. When such troubles occur, the tape can not be wound completely from one reel to another. In addition, an abrupt reduction of tie rotation of the capstan motor caused by a load applied during a high-speed running of the tape may cause a breakage of the tape.
It is therefore an object of the present invention to provide a tape transport apparatus wherein the tape running is achieved without applying a load to a capstan motor even if a winding load increases during a fast-forward running mode or a rewinding running mode.